Underseat electric heater for street cars and the like



Sept. 29, 1925.

W. G. HARTWIG UNDERSEAT ELECTRIC HEATER FOR .STREET CARS. AND THE LIKE Filed April 26, 1924 -OOOOOO 000000 000000 0000000 OOOOOOOO O OOOO 'OOOOOOO Patented Sept. 29, 1925.

UNITED STATES PATENT OFFICE.

WILLIAM G. HAR'IWIG, OF CHICAGO, ILLINOIS, ASSIGNOR TO RAILWAY UTILITY COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

UNDERSEAT ELECTRIC HEATER FOR STREET CAR-S AND THE LIKE.

Application filed April 26, 1924.

T all whom it may concern:

Be it known that I, VILLIAM G. HART- wie. a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois. have invented certain new and useful Improvements in Under-seat Electric Heaters for Street Cars and the like, of which the following is a specification.

My relation relates more particularly to the mounting and inclosure of electric heating elements beneath the seats of passenger cars and it has for its object to provide mountings and enclosures which permit ready access to the heating elements and their connections, which protect the heating elements from accidental injury and the car, seat and passenger using the seat from injury and danger. and which are cheap to manufacture, durable and sightly.

In the drawing accompanying and forming a part of the specification Fig. 1 is an isometric view of the preferred form of my invention, showing the casing or enclosure partly broken away to reveal the interior thereof; Fig. 2 a plan view of the same with the top or cover plate removed and parts shown broken away and in section; Fig. 3 a transverse vertical section on the plane of the line 33 of Fig. 1; Fig. 4 a similar view on the vertical plane of the line 4-4 of Fig. 2 and Fig. 5 a horizontal section of a detail on the line 5-5 of Fig. 1. The parts are identified by the same reference characters wherever they occur in the several views.

My invention is particularly intended and adapted for use with flat heating elements 6 which may be of a character found on the market and are not of my invention. The form of heating element in connection with which I have chosen to disclose my inven- .tion, and which is Well known on the market, comprises a strip of resistance metal 7 embedded in an insulating material 8, the whole being inclosed in a sheet iron sheath 9. The ends of the sheath beyond the resistor and embedding material are bent together as at 10 to form lugs by which the heater may be coiweniently mounted on the support therefor. The opposite ends of the heating strip 7 are connected to terminal posts 8 one of which is-shown in Fig. 5 and which comprises a flange ll embedded in the insulating material within the sheath and a socket 12 which extends through the sheath but is innut and the sheath.

Serial No. 709,086.

sulated therefrom. A double screw 13 hav ing an intermediate nut portion 1 L formed integral therewith is screwed at one end into the socket 12. there being interposed a mica or other insi'ilating washer 15 between the The screw 13 forms a binding post as will presently appear. The entire element as so far described, however is of previous invention and is not claimed herein.

Preferably two of the heating elements 6 as above described are mounted in each housing. For this purpose a pair of brackets 20 of insulating material are mounted in the respective opposite ends of the housing and support the ends of the heating elements on their respective opposite sides. These brackets are alike and the description of one will serve for both. Each bracket is substantially T-shaped as seen in Figs. 3 and 4c and the base 21 thereof is secured to the bottom 22 of the enclosing casing by screws H3. The opposite flanges or wings 24 of the bracket support hangers 25, to which are secured the ends of the respective heating elements. The horizontal member 26 of each hanger is secured by a pair of screws 27 to the insulating bracket and the depending leaf 28 thereof is perforated to receive the screw 29 on which the lug of the heating element is mounted. The "bent connector 30 is perforated at its respective opposite ends, one end thereof receiving the screw 29 and the other end the double screw 13 of the heater terminal previously described. A nut 31 secures the bent connector on the double screw. The end of the heating element is mounted on an insulating sleeve 32 which has a flange bearing upon the connector 30 and surrounds the screw-bolt 29. The sleeve projects through the hole 34 in the heating element so as to support and insu late the latter from the screw bolt and an insulating washer 35 surrounds the outer end of the insulator and bears upon the sheath of the heating element. A metal washer 35 is interposed between the insulating washer and the securing nut 36 and the nut lock 37 is also preferably used to prevent the accidental turning of nut 36.

Either of the screws 27 by which the hangers are attached to the bracket may be used as a binding post for securing the lead wire. It will now be seen that the heating elements are securely suspended from the of the casing.

brackets independently of the binding posts by which electric connections are made to the resistor, and the binding posts are connected by the respective connectors 30 to the depending arms 28 of the hangers which, as above described, may be connected directly to the lead Wires.

The boxing or casing as shown is substantially rectangular.

The bottom and sides are preferably made of a single sheet of metal, the upper edges of the sides 40 being bent outwardly and then inwardly to form re-enforcing ribs 41. The casing is provided with supporting brackets 42, preferably of heavier sheet metal than the body of the casing, which brackets are bent into Z-shape, the upper leaf 43 being perforated for the insertion of attaching screws, the intermediate leaf 42 substantially vertical, and the lower leaf 44 extending at its edges into the U-shape recesses 45 formed in the upper edges of the side walls by bending them as heretofore described. Preferably the supporting brackets are cut away intermediate their ends as at 46 to afford more convenient access to the contents of the casing when required and are spot-welded to the side walls End walls 47 close the ends of the casing and may be spot-welded or otherwise secured to the side and bottom walls thereof.

A hole is formed in one of the end walls for the passage of the wires or leads to the heaters in which is secured the end of the pipe 49. Preferably guides 50 are formed in the respective lower corners of the casing to receive the wires 51 leading to the ends of the heaters remote from the outlet opening 49. I prefer to form holes 53 in the end wall in register with the channels or guides 50 for convenience in inserting the wires in the latter. It will be understood that before the casing is scoured in position on the bottom of the seat it is provided with a cover and in Fig. 4 I have shown such a cover 56 of sheet metal, the edges 57 of which are bent downward to deflect the heat currents away from the seat and permit easy cleaning of the top 21.

By the above described construction I have provided a substantial and safe mounting for the electric heating elements and a casing which is substantial, easy to manufacture and affords convenient access to the heaters when required.

The screws 27 by which the hangers are secured to the insulating blocks are readily accessible from the top of the casing so that in case it is necessary to repair or remove either or both of the heating elements this mav be readily done. The construction is such, moreover, that the heating elements are practically surrounded by the current of air rising through the perforated bottom wall and passing upwardly and then laterally through the openings in the side walls of the heater.

I claim:

1. In an electric heater of the class described, a casing, a pair of insulating blocks secured to and rising from the bottom of said casing, a pair of hangers secured to the upper faces of the respective blocks and depending therefrom, a heating element connected to said hangers at its opposite ends and electric connections for transmitting current through the heating element.

2. In a heater of the class described, a casing, a pair of blocks of insulating ma.- terial mounted on the bottom of the casing in opposite ends thereof and projecting upwardly therefrom, L-shaped hangers secured at one end upon the u per faces of the re specv-tive blocks and epending along the sides thereof, an electric heating element secured at its ends to the respective hangers and connections for transmitting current to the heating elements.

3. In an electric heater of the class described, a casing open at its upper side and adapted to be attached to a seat or the like, a pair of T-shaped blocks of insulating ma terial mounted on the bottom of said casing, pairs of L-shaped hangers dependin from opposite sides of the respective bloc s and secured to the upper surfaces thereof, a pair of heating elements secured to said hangers at their opposite ends and connections for transmitting current to said heating elements.

4. In a heater of the class described, a casing open at its top, a pair of brackets of insulating material secured to the bottom of the casing adjacent its opposite ends, a pair of hangers fastened to the tops of the respective brackets and depending therefrom, a heating element secured at its respective opposite ends to said hangers, terminal sts at the respective opposite ends of said eating element, and connectors between the respective terminal posts and the adjacent hangers.

5. In an electric heater of the class described, a pair of brackets of insulating material adjacent opposite ends thereof, l.- shaped hangers secured to the tops of the respective brackets and depending alongside thereof, a heating element comprising a sheath and a resistor wire therein having projecting terminals, there being holes in the respective ends of the sheath, screw bolts extending through the respective hangers and ends of the heating element, connectors from said screw bolts to the respective ad- 1 5 jacent terminals of the heating element, said connectors making contact with the respective hangers, and means for insulating said bolts from said sheath.

6. In a heater of the class described, comprising a casing having bottom, end and side walls, the upper edges of the side walls being bent to form U-shaped strengthening ribs and brackets for supporting said heater partially extending into said grooves, and having attaching flanges, heating elements mounted in said casing and means for transmitting current to said elements.

7. In a heater of the class described, a casing comprising bottom, side and end walls, the edges of the end walls being bent outward and then inward to form grooves, T-shaped brackets at the respective ends of the casing the edges of which extend into and are secured in said grooves, heating elements mounted in said casing and means for transmitting current to said heating elements.

8. In a heater of the class described, a casing having bottom, side and end Walls, insulating brackets secured to the bottom wall adjacent the opposite ends thereof, a heating element secured at its respective opposite ends to said brackets, bridge pieces secured within the opposite lower corners of the easing to form conduits with the adjacent walls of the casing, there being holes in the end walls of the casing substantially registering with said conduits.

9. In a heater of the class described, a casing, a heating element in the casing comprising a conducting metal strip, a body of insulating refractory material surrounding the strip, a sheath enclosing the strip and insulating body and extending beyond the same at its opposite ends, the ends of the sheath being flat and having openings therethrough, bolts adapted to receive supporting brackets extending through the perforations at the respective opposite ends of the sheath, a flanged sleeve of insulating material surrounding each bolt and extending through the perforations in the sheath to insulate the bolt from the latter, a washer of insulating material surrounding the sleeve on the end thereof opposite to the flange thereof, a nut on the bolt, binding posts on the ends of the conducting strip extending through holes in the sheath and connections from said posts to said bolts.

\VILLIAM G. HARTW'IG. 

